39 



When the second brood appears, in July or early August, the tepts 

 are so much more numerous that they attract more attention and the 

 insects grow so fast that unless measures are taken at once the in- 

 fested trees may suffer defoliation. The nest or tent is a shelter 

 merely, and from it the caterpillars work out to feed in every direc- 

 tion, returning to rest at certain periods of the day. Late in August 

 and during the first half of September the larvae of the second brood 

 leave the nests and wander, sometimes for considerable distances, be- 

 fore they change to the pupal stage. 



The first brood seems to suffer little from parasitic attack, and 

 most of the caterpillars complete the change to the adult condition. 

 The second brood is, as a rule, greatly parasitized, and a very small 

 percentage of the specimens that become full grown complete their 

 transformations. This accounts for the fact that the spring brood is 

 usually a small one, and also for the fact that sometimes, when condi- 

 tions favor the caterpillars rather than the parasites, the species runb 

 away from its checks and for a year or two will become plentiful 

 enough to do considerable mischief. 



Remedial Measures. 



In the garden this insect is readily controlled. As soon as the first 

 trace of a nest is noted it should be torn out and the entire brood 

 killed. As the tent then takes in only one or two leaves this is an 

 easy matter, and there is no danger of mutilating any tree or shrub. 



On shade trees, where the nests cannot be readily gotten at, the 

 foliage at the points where the nests are observed should be sprayed 

 with an arsenical poison. There is no necessity for spraying the entire 

 tree, because the insects feed only in the immediate vicinitj' of the nest 

 so long as there is anything to eat at that point. If the second brood 

 becomes abundant and nests are seen all over the tree, then, of course, 

 the entire tree should be sprayed. The caterpillars succumb very 

 readily to arsenical poisons while they are still small; therefore, the 

 earlier the spraying is done, the less the foliage will be eaten and the 

 more easily will the insects be destroyed. 



